Non-Volatile Memory Express (NVMe) is a standard for accessing non-volatile storage media attached via PCI Express (PCIe) bus. NVMe may be used with a variety of non-volatile storage media, such as solid state drives (SSDs). Part of the NVMe standard includes an NVMe virtualization environment. Virtualization environments may use an NVM subsystem with multiple controllers to provide virtual or physical hosts direct I/O access.